1. Field of the Invention
This invention relates to surgical fastening apparatus, and specifically to an improved surgical fastening apparatus containing a locking mechanism.
2. Background of the Art
Surgical fastening apparatus for simultaneously applying an array of surgical staples or other types of fasteners are known in the art. Such apparatus are used for suturing body tissue such as, for example, intestinal and gastric walls with spaced parallel rows of longitudinally aligned staples. These surgical stapling apparatus reduce the time of wound closure in a surgical procedure.
Typically these devices include a fastener holder disposed on one side of the tissue to be fastened, and an anvil assembly parallel to the fastener holder on the other side of the tissue to be fastened. The fastener holder is moved linearly towards the anvil assembly so that the tissue is clamped between them. The fasteners are driven from the fastener holder so that the ends of the fasteners pass through the tissue and form finished fasteners as they make contact with the anvil assembly, thereby producing an array of finished fasteners in the tissue. Optionally, the fastening apparatus may include a knife mechanism for creating an incision between rows of fasteners. The fasteners can be made of metal, non-absorbable polymers, or bioabsorbable polymers such as polyglycolide, polylactide, and copolymers thereof.
In common use are apparatus in which the fastener holder comprises a disposable cartridge removably mounted in or on a permanent actuator for supporting and actuating the cartridge. The cartridge is disposable after a single use, i.e. after the fasteners are fired. The permanent actuator is reusable in the same surgical procedure after reloading with a fresh cartridge, and is reusable in another surgical procedure after cleaning, sterilizing, and reloading. Also known are disposable surgical apparatus, in which the entire apparatus is disposed of after use. Examples of surgical stapling apparatus may be found in U.S. Pat. No. 4,354,628 to Green, U.S. Pat. No. 4,665,916 to Green, and U.S. Pat. No. Des. 283,733 to Rawson et al.
In the use of surgical fasteners the possibility arises that the fastener apparatus may be actuated when the cartridge is empty of fasteners. This can occur when the apparatus has been fired once, but the cartridge is not reloaded or discarded. This can also occur if the apparatus is inadvertently reloaded with a spent cartridge. Under such circumstances the fastening apparatus will fail to suture the body tissue, which can cause harm to the patient and result in the surgeon's loss of valuable time. The risk of harm is greatly increased if the apparatus contains a knife mechanism, since it will create an unsealed incision. To eliminate these dangers to the patient it would be beneficial to provide a mechanism which alerts the user that a new cartridge is required. It would further be beneficial if such a mechanism can provide a lock to actually prevent the surgeon from trying to fire a cartridge that has already been fired and prevent reloading of a spent cartridge. This would save valuable time and reduce the risks to the patient. The present invention relates to such an apparatus.